EP0950813B1 - Swivel bearing for a swash plate in an axial piston machine - Google Patents

Description

The invention relates to an axial piston machine according to the preamble of Claim 1, as z. As described in DE 195 38 835 C1 or EP 0 327 012 B1 is.

In an axial piston machine of this type, the pivot bearing is in functional operation exposed to high loads. This is partly due to the design, as in Functional operation all pistons of the high pressure side axially supported on the swash plate and therefore the pivot bearing has to absorb large bearing forces. at Axial piston machines whose swashplate in functional operation, d. H. under load is adjustable, it also requires large adjustment forces to the swash plate to be able to adjust and adjust the flow rate of the axial piston machine can. To the surface pressure on the bearing bodies of the pivot bearing possible To keep low, one has already gone over to the pivot bearing in the sense of a so-called cradle with a relatively large radius cylinder section-shaped form, so that on both sides of the axis of rotation of the axial piston machine is about over the entire cross-sectional dimension extending cylinder section-shaped Storage areas are available. The surface pressure can be further reduced, if the pivot bearing is designed as a plain bearing whose bearing surfaces in Functional operation sliding against each other. In a plain bearing are the However, adjusting the chafing wheel to be overcome frictional forces relatively large. Therefore, you have the pivot bearing already as a rolling bearing with between the Cylinder-shaped bearing surfaces arranged rolling elements formed (DE 195 38 835 C1), which takes place due to a roll friction occurring during functional operation allow easier adjustment of the axial piston machine, especially under Load. In a designed as a rolling bearing pivot bearing are the bearing surfaces However, only punctiform in spherical or linear in cylindrical Rolling loaded, so that in functional operation large surface pressures resulting in increased wear and reduced service life of the Swing bearings lead, if not high-quality materials are used, which are expensive are. A considerable disadvantages is also that the bearing body of the weigh-like Schragscheibe and the bearing body of the housing one another exactly must have a coordinated radius of curvature, wherein the radii of curvature not allowed to change significantly even under heavy load.

In the axial piston machine described in EP 0 327 012 B1, the hollow cylindrical bearing surface of the housing-side bearing body of the pivot bearing with a view to improving the sliding property and reducing wear designed a reinforced plastic coating.

The invention is based on the object in an axial piston of the above specified type to improve the storage of the swash plate.

This object is solved by the features of claim 1. advantageous Further developments of the invention are described in the subclaims.

In the embodiment according to the invention, at least one bearing body of the segmented with each other cooperating bearing body of the pivot bearing. The bearing segments formed thereby are by a plastic or elastic Means, e.g. B. an intermediate substance, supported on the associated bearing body or coupled. The bearing segments meet the requirements of the Form accuracy due to their location, being due to the elastic or plastic Supporting an automatic adaptation to the shape of the bearing surface of the respective Enable abutment body. The plastic agent may be a act such substance, which is only temporarily plastic, z. B. in the assembly of Abutment body or a corresponding model, and then in a position of Hardened bearing segments, in which this on the abutment surface of the abutment body issue. With an elastic means, the bearing segments are able to move constantly to adapt to the shape of the counter bearing surface. Both in a plastic as well with an elastic means the bearing segments meet the requirements of the Form accuracy through their overall positional accuracy.

As a plastic precursor z. B such a substance, temporarily is plastic and after assembly or the system of the abutment surface of the associated abutment body hardened on the bearing segments, causing them Bearing segments are fixed and specify the shape of the associated "storage area".

It is possible within the scope of the invention that the bearing segments directly abut each other and thereby form a guide or a distance from each other and are stored in an associated guide.

It is within the scope of the invention also possible to make the arrangement so that the Bearing segments with respect to their position to the abutment surface adjustable and in the respectively set position detectable or against movement of the Counter bearing surface are limited away. This can be done in a simpler and more advantageous way hydraulically, namely by a hydraulic fluid, the counter bearing surface applied to opposite ends of the bearing segments, which on the one hand the plant the bearing segments on the abutment surface and on the other a removal of the Bearing segments is prevented by the abutment surface.

In the embodiment of the invention, a bearing body is segmented, so that between the bearing segments when they lie against each other, there is a gap, or if they are spaced from each other, there is a gap. This ensures the independence of the bearing segments from each other.

In the context of the invention, the means may be intermediate elements, wherein such an intermediate element may be elastic or plastic or two in each case Intermediate elements may be provided, one of which in the above sense plastic and the other can be elastic. In this case, the intermediate elements can Plastic be formed.

Through the use of matrix elements, both the precursor and the Take up intermediate elements as well as the bearing segments are cheap and in terms of geometry diverse solutions possible.

The invention allows sufficient in the area of the associated storage area large bearing component with good dimensional accuracy in all pivotal positions where a expensive and expensive production is avoided. Therefore, the invention is suitable very good for difficult to work materials, especially ceramics and / or for a concave shape of the bearing surface that is more difficult to manufacture than a convex one Shape.

In the subclaims features are included, which are the elastic or plastic Improve properties of bearing segments, a simple arrangement of Lagersegmente result and a simple production while ensuring a enable simple and small construction.

Fig. 1

eine erfindungsgemäße Axialkolbenmaschine der Schrägscheibenbauart in der Seitenansicht, teilweise geschnitten;

Fig. 2

die in Fig. 1 mit X gekennzeichneter Einzelheit in vergrößerter und in der Zeichnungsebene um 90° verdrehter Darstellung;

Fig. 3

die Einzelheit X in abgewandelter Ausgestaltung;

Fig. 4

einen Lagerkorper nach Fig. 3 in der Draufsicht;

Fig. 5

die Einzelheit X in weiter abgewandelter Ausgestaltung;

Fig. 6

einen Lagerkörper des Schwenklagers nach Fig. 5 in der Draufsicht;

Fig. 7

die Einzelheit X in weiter abgewandelter Ausgestaltung;

Fig. 8

die Einzelheit X in weiter abgewandelter Ausgestaltung;

Fig. 9

ein Lagersegment in perspektivischer Darstellung;

Fig. 10

ein Lagersegment in abgewandelter Ausgestaltung in perspektivischer Darstellung; und

Fig. 11

ein Lagersegment in weiter abgewandelter Ausgestaltung in perspektivischer Darstellung.

The invention and further achievable by them advantages will be explained in more detail with reference to advantageous embodiments and drawings. Show it

Fig. 1

an axial piston machine according to the invention of the swashplate type in the side view, partially cut;

Fig. 2

the marked in Figure 1 with X detail in enlarged and rotated in the plane of the drawing by 90 ° representation.

Fig. 3

the detail X in a modified embodiment;

Fig. 4

a bearing body of Figure 3 in plan view.

Fig. 5

the detail X in a further modified embodiment;

Fig. 6

a bearing body of the pivot bearing of Figure 5 in plan view.

Fig. 7

the detail X in a further modified embodiment;

Fig. 8

the detail X in a further modified embodiment;

Fig. 9

a bearing segment in perspective view;

Fig. 10

a bearing segment in a modified embodiment in perspective view; and

Fig. 11

a bearing segment in a further modified embodiment in perspective view.

The axial piston machine in Schwenkscheibenbauart has a simplified illustrated Housing 1, the housing interior 2 at one end by a so-called terminal block 3 is closed with a control disk 4. At the Inside the control disk 4 is a cylinder drum 5, the rotationally fixed on a Drive shaft 6 is mounted, which is a connection block 3 arranged opposite Housing part 7 penetrated in a hole to the outside. The drive shaft 6 is by means Rolling bearings 8, 9 rotatably mounted in the housing 1. The axis of rotation is designated 6a. Between the cylinder barrel 5 and the housing part 7 is located in Housing interior 2 a chute 11, of the drive shaft 6 in a Punch space 11 a is penetrated, and with respect to the rotation axis 13 is non-rotatable However, about a perpendicular to the axis of rotation 6a extending pivot axis 12 in one Swivel bearing 13 is pivotally mounted in the housing interior 2. The pivot bearing 13 is a sliding bearing with a cylindrical portion concave bearing surface 14 at a formed by the housing part 7 first bearing body 15 and a cylindrical portion-shaped convex bearing surface 16 at one through the swash plate 11 formed bearing body 17. The bearing surfaces 14, 16 can over the entire Transverse dimension of the housing part 7 and / or the chute 11 extend, or it can also on both sides of the hole clearance 11a each have a pivot bearing 13 with be described above bearing surfaces 14, 16 of narrow construction.

In the cylinder drum 5 are several approximately in the longitudinal direction of the axis of rotation 6a extending working cylinder 18 distributed in the form of holes in the circumferential direction arranged in which pistons 19 are mounted longitudinally displaceable, whose Swash plate 11 facing piston heads 21 by with the piston heads 21st pivotally connected sliding shoes 22 on a flat sliding surface 23 of the Swash plate 11 abut and by a simplified illustrated retaining device 24 are held on the sliding surface 23 in a conventional manner.

The axial piston machine has a simplified and designated 25 Throughput volume adjustment device which engages the swash plate 11, and with the swash plate 11 to increase or decrease the Throughput volume in different positions and pivoted in the respective Position is detected.

The bearing body 15 of the housing 1 and / or the bearing body 17 of the swash plate 11th is segmented in each case in the area of the associated bearing surface 14, 16. The result formed bearing segments 31 are by a plastic or elastic means 32 on associated bearing body 15, 17 supported and thus held, where they with their the Bearing body 15, 17 facing away from free end faces 31 a bearing part surfaces 14 a of associated bearing surface 14 can form. In the present Embodiments, only the bearing surface 14 of the bearing body 15 is segmented.

The bearing segments 31 are slidably guided in a radial guide 33, wherein this guide 33 may be formed by guide holes 34 in which the Bearing segments 31 are slidably guided with little movement play, and on the means 32 also disposed therein, see Fig. 2, the Simplification reasons only one bearing segment 31 shows.

The bearing segments 31 can be random in the area of the associated bearing surface 14, 16 distributed or arranged in ordered positions, in particular in rows R1, R2, wherein at least one, transverse to the pivot axis 12 extending row R be provided can, and wherein the bearing segments 31 along the pivot axis 12 approximately over the entire width b of the associated bearing surface 14, 16 extend and transverse to Pivot axis 12 can be arranged side by side and form the row R. see FIG. 6. The bearing segments 31 can also be arranged in several, as shown in FIG. be arranged transversely and along the pivot axis 12 extending rows R1, R2, wherein the bearing segments 31 offset from each other in adjacent rows can be arranged. The Fuhrungslocher 34 can in the bearing body 15 or in an attached inside or outside cylindrical portion wall portion 35th be arranged, which may also be a layer on the bearing body 15 and a Matrix 35a forms. The pivoting directions of the swash plate 11 are by a Double arrow S clarifies.

The guide 33 may also be formed by the bearing segments 31 laterally with Motion play adjacent to each other so that each laterally adjacent Bearing segments 31, the guide 33 for an interposed bearing segment 31st form. As a result, specially incorporated guide holes 34 shown in FIG. 2 omitted. It is also possible for the matrix 35a to be plastic or elastic To form means 32 in the sense of the wall portion 35, as shown in FIG. 5. It is also possible, the bearing segments 31 at its the associated bearing body 15 facing Side with the means 32 or the matrix 35a or the layer to connect, for. B. by Gluing, so that the bearing segments 31 with the means 32 or the matrix 35 a or the Layer form a firmly connected unit. In such an embodiment, the Guide 33 formed by the material of the matrix 35a or the layer, so that it the side surfaces of the bearing segments 31 no guide, z. B. no guide holes 34, and therefore requires the bearing segments 31 a lateral distance in the sense of Groove may have from each other. It is also possible, the wall part 35 or the Matrix 35a in the longitudinal direction of the pivot axis 12 and / or in the Swing direction (see double arrow S) in another way on the bearing body 15 to secure, z. B. form-fitting, by lateral boundaries, not shown, or Attacks. When forming the matrix 35a as a coated layer, the Attachment to the bearing body 15 by the layer order and thereby caused connection with the bearing body 15 may be formed.

It is also possible to form the elastic means 32 by a compression spring 36, the in the embodiment of FIG. 7 is formed by a helical spring and with the associated bearing segment 31 in an associated guide hole 34 in the matrix 35a or may be arranged in the bearing body 15.

Between the bearing surface 16 of the swash plate 11 and the surface 35b facing it of the bearing body 15 or the wall portion 35 or the matrix 35a is a distance a present, with which the bearing segments protrude.

In an embodiment with an elastic means 32 whose elasticity or Modulus of elasticity dimensioned so large that the example as against the bearing body 17th Directional arrows shown resistance forces W are preferably sized larger, as the load to be absorbed by the pivot bearing 13, which is indicated by the arrow L. is. Due to the elasticity of the elastic means 32 or the by the Bearing part surfaces 14 a formed bearing surface 14 elastically yielding and they can in Functional operation of the axial piston machine depending on the size of the load L more or less be moved to the bearing body 15 out, z. B. at peak loads. This is irrelevant, as a result of the delivery volume or the performance of the Axial piston machine is not changed.

However, the sum of the elastic resistance forces W can also be smaller than that Last L or as load peaks. In such a case, the bearing segments can 31 as far as the bearing body 15 towards shift that the elastic means 32 a Movement stop forms or the bearing segments 31 so far in the guide holes 34th immerse that the bearing body 17 facing surface 35b of the wall portion 35 or the matrix 35a, the bearing surface 16 additionally forms. This can be especially at Load peaks additional storage areas are created.

The plastic means 32 may be such a material that is temporarily plastic and after an arrangement of the bearing body 17 in the position position, for. B. in the Assembly, hardened. In this case, an automatic positioning of the bearing segments 31 takes place by their positional adaptation to the bearing surface 16th

In the embodiment of FIG. 8, the plastic or elastic means 32 is through a hydraulic medium, in particular by the hydraulic means of Axial piston machine formed, which is under pressure and in the guide holes 34 arranged bearing segments 31 against the bearing body 15 is supported and with the guide holes 34 connected channels 37 of an associated hydraulic Supply system is fed. A hydraulic medium can be an elastic one Means 32 form when the associated hydraulic supply system Pressure accumulator, z. B. in the form of an elastic bellows, is assigned.

If in each case a passage channel 38 is arranged in the bearing segments 31, the preferably centrally in the shape of the bearing surface 16 adapted bearing part surface 14, preferably in the region of a recess 39, opens, then not only one Lubrication of the bearing surfaces 14, 16, but also a reduction in Surface pressure due to a hydrostatic pressure relief.

FIGS. 9 to 11 show different cross-sectional shapes for the bearing segments 31, which are preferably of prismatic form. Fig. 8 shows a circular Cross-sectional shape, which is preferably suitable for drilled guide holes 34. Fig. 10 shows a rectangular cross-sectional shape, in particular for a Embodiment of FIG. 6 is suitable, in which the greater dimension designated L1 is directed parallel to the pivot axis 13.

In all embodiments, the one part of the bearing surface 14 forming free End face 31a of the bearing segments flat or to the curvature of the bearing surface 14th be adapted and thus correspond to this curvature. In the former case arises at present embodiment, only a line-shaped surface contact between the bearing segments 31 and the bearing surface 16 of the bearing body 17. In the second case (Fig. 11) there is a flat contact between these parts, whereby the Surface pressure is significantly reduced and optimal.

In the context of the invention, the bearing segments 31 in accordance with the reverse Way instead of the bearing body 15 may be arranged on the bearing body 17. It is also possible to form both bearing body 15, 17 with bearing segments 31 accordingly.

An embodiment in the case of only one of the bearing bodies 15, 17 with bearing segments 31 is formed, is particularly advantageous because the bearing body 15, 17 of the no Bearing segments 31 has by its bearing surface 14 or 16 a rigid Specifies bearing surface shape to which the bearing segments 31 adapt.

Claims (10)

1. Axial piston machine with a housing (1), in which a plurality of pistons (19) are mounted axially displaceably in cylinder bores (5) and are displaceable by a swash plate (11) which is mounted, pivotably about a pivot axis (12) running transversely to the axis of rotation (6a) of the axial piston machine, in a pivot bearing (13) having a first bearing body (15) arranged on the housing (1) and a second bearing body (17) arranged on the swash plate (11),
   characterised in that the bearing body (15) of the housing (1) or the bearing body (17) of the swash plate (11) has bearing segments (31) which are supported on the associated bearing body (15) by a plastic or elastic means (32).
2. Axial piston machine according to Claim 1,
   characterised in that the bearing segments (31) are each radially guided with respect to the pivot axis (12) in a guide (33) arranged on the associated bearing body (15) or on the means (32).
3. Axial piston machine according to Claim 1 or 2,
   characterised in that the means (32) is formed by a matrix (35a) or layer arranged on the associated bearing body (15).
4. Axial piston machine according to Claim 2 or 3,
   characterised in that the guide (33) is formed by a guide hole (34) in the associated bearing body (15) or in the matrix (35).
5. Axial piston machine according to one of the preceding claims,
   characterised in that the bearing segments (31) each laterally adjoin one another with movement play or have a space between one another.
6. Axial piston machine according to one of the preceding claims,
   characterised in that the bearing segments (31) are arranged in one or more rows (R, R1, R2) each running parallel to the pivot axis (12) or in the pivoting direction (S).
7. Axial piston machine according to Claim 1,
   characterised in that the bearing bodies (15, 17) or the matrix (35a) and the opposite bearing body (17) have a space (a) between one another which is bridged by the bearing segments (31).
8. Axial piston machine according to one of the preceding claims,
   characterised in that the means (32) is a plastic hardening or setting material or an elastic material or a compression spring (36), in particular a helical spring, or a hydraulic medium.
9. Axial piston machine according to one of the preceding claims,
   characterised in that the free front face (31a) of the bearing segments (31) is plane or is curved in accordance with the shape of the bearing surface (16) of the opposite bearing body (17).
10. Axial piston machine according to Claim 9,
    characterised in that a channel (38) connected to the hydraulic medium extends through each of the bearing segments (31) and opens into the front face (31a) thereof, in particular into a recess (39) of the front face (31a).

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